1. Field of the Invention
The present invention relates to an air bag apparatus installed at an instrument panel and constituted to develop an air bag folded to contain at inside of the case.
2. Description of the Related Art
In a related art, according to an air bag apparatus having the above-described constitution, an air bag is provided with a through hole penetrated in a left and right direction (refer to, for example, JP-A-6-344844).
However, the air bag apparatus of the related art is constituted such that the through hole provided at the air bag is not closed even in finishing to expand the air bag. That is, according to the air bag of the related art, a dispersion is brought about in a function of constraining the passenger at a portion thereof on a side of the passenger in a state of finishing to expand the air bag since the through hole penetrated in the left and right direction is provided at a vicinity of a center thereof. For example, according to the air bag apparatus of the related art, when the head portion of the passenger interferes with a portion of the air bag which has been finished to expand constituting a vicinity of a center axis of the through hole, the air bag is considerably recessed to deform to a side of the through hole to narrow an inner diameter of the through hole. Further, when the head portion of the passenger interferes with a portion thereof remote from the center axis of the through hole, an amount of recessing the air bag is small. Therefore, according to the air bag apparatus of the related art, the function of constraining the passenger is dispersed by a physical constitution and an attitude of the passenger and there is a concern of being unable to stably protect the passenger.
Incidentally, an air bag apparatus for protecting a passenger is included at inside of an instrument panel arranged in front of a passenger seat of a vehicle. An air bag is folded to contain in a case constituting the air bag apparatus and an inflator is operated in impacting the vehicle. Further, by introducing a generated gas at high pressure into the air bag, the air bag is rapidly expanded to develop to the passenger to thereby constrain movement of the passenger by an inertia force.
There is proposed the above-described air bag apparatus disclosed in JP-A-11-170955. According to the air bag apparatus, an initial developing speed of the air bag to the rear side is reduced by providing an inner bag in the air bag.
According to the air bag apparatus disclosed in JP-A-11-170955, a portion of the air bag needs to press to an instrument panel or a windshield by the inner bag and a position of mounting the air bag apparatus to the vehicle is limited.
Incidentally, according to an air bag apparatus of a related art, an air bag in a bag-like shape is constituted substantially by a shape of a cone including a passenger side wall portion arranged substantially along a vertical direction on a side of the passenger and a peripheral wall portion narrowed substantially in a shape of a cone from an outer peripheral edge of the passenger side wall portion to a front side of a vehicle as a shape in finishing to expand to develop the air bag (refer to, for example, JP-A-2002-255004). The air bag is constituted to arrange a gas flow inlet as an opening face substantially along a horizontal direction at a front side of a lower side of the peripheral wall portion in finishing to expand to develop the air bag and a peripheral edge of the gas flow inlet is attached to a case.
The air bag is contained in the case by transversely folding the air bag for making a crease in a left and right direction and vertically folding the air bag for making a crease in a front and rear direction after previously folding the air bag, and a previously folding shape thereof after finishing to previously folding the air bag is constituted by a shape of arranging a portion of a vicinity of an upper edge of the passenger side wall portion at a position opposed to the gas flow inlet and overlapping the passenger side wall portion on the lower side of the peripheral portion to flatten.
According to the air bag apparatus, in expanding to develop the air bag, the air bag is expanded to develop to a rear side of a vehicle by making an expanding gas flow from the gas flowing inlet to project to push to open doors arranged at an instrument panel while resolving the creases constituted by transversely folding and vertically folding the air bag, at that occasion, since the portion proximate to the upper edge of the passenger side wall portion is arranged at the position opposed to the gas flow inlet, a portion proximate to the upper edge of the passenger side wall portion opposed to the gas flow inlet is strongly pushed up to an upper side by a pressing force of the expanding gas at an initial stage of making the expanding gas flow more precedingly than other portion of a portion on a side of a lower edge of the passenger side wall portion or the like and therefore, the passenger side wall portion is easy to arrange to be along substantially in the vertical direction
Further, when the portion at the vicinity of the upper edge of the passenger side wall portion is strongly pushed up, the portion can contribute also to swiftly resolving the creases constituted by transversely folding and vertically folding the air bag and therefore, the passenger side wall portion can widely be developed, in expanding to develop the air bag, the passenger side wall portion which is brought into a state of being substantially orthogonal to the peripheral edge of the gas flow inlet can be arranged to be swiftly along substantially the vertical direction and the air bag can be developed in a widely opened state such that the pressing force is not partially operated to a side of the passenger.
However, although according to the air bag apparatus of the related art, in expanding to develop the air bag, the passenger side wall portion can be moved to the rear side of the vehicle in the state of constituting the wide face arranged substantially in the vertical direction, in the case in which an obstacle having a height up to a vicinity of a height of the instrument panel is arranged at a vicinity of the instrument panel, there is a room for improvement in finishing to expand the air bag while restraining interference with the obstacle.
Incidentally, according to an air bag apparatus of a related art, in expanding to develop an air bag folded to contain in a case, an expanding gas is made to flow thereinto from a gas flow inlet, push to open doors arranged at an instrument panel and expanded to develop to a rear side of a vehicle. Further, according to the air bag apparatus of the related art, the air bag is folded to contain to project to a side of a passenger in a state of widely opening a face constituting the side of a passenger and in a state of restraining a moving speed thereof such that the pressing force is not operated partially to the side of the passenger in expanding to develop the air bag (refer to, for example, JP-A-2002-255004).
Further, according to the air bag apparatus of the related art, a vicinity of an upper end of the face arranged substantially orthogonally to the gas flow inlet to constitute the side of the passenger in finishing to expand the air bag is arranged to be opposed to a gas flow inlet in the contained state. Therefore, in expanding to develop the air bag, the face on the side of the passenger is developed to be along substantially in a vertical direction. However, according to the air bag apparatus of the related art, there is a room for improvement in reducing a speed of moving the face constituting the side of the passenger.
Incidentally, in a related art, there is known an air bag apparatus arranged with a supporting member for supporting an expanded portion of an air bag for protecting a passenger on a front side (refer to, for example, JP-A-11-227553).
According to the air bag, an expanded portion of a region of protecting the head portion of the passenger is supported by the supporting member comprising an air bag arranged on a front side thereof (refer to FIG. 1 of JP-A-11-227553).
However, according to the air bag apparatus of the related art, the expanded portion for protecting the head portion of the passenger is supported by the supporting member, an expanded portion for protecting the chest and the belly portion of the passenger is not supported by the supporting member, depending on elastic performance of the supporting member, by presence or absence of the supporting member, the chest and belly portion of the passenger is constrained by the protecting expanded portion with excellent positioning performance, however, there is a concern that the head portion of the passenger is not constrained by the protecting expanding portion of the head portion.